System and method for reducing noise in sensors with capacitive pickup

Abstract

An apparatus and method are provided for reducing noise in a capacitive sensor (200). One apparatus includes a gain stage (210) including an output, the gain stage configured to generate a first signal having a noise component and a second signal having a desired output component and the noise component, and a filtered-sampling stage (250) having an input coupled to the gain stage output, the filtered-sampling stage configured to sample the first signal, store the first signal, and subtract the first signal from the second signal to produce a desired output signal. A method includes generating a first signal having a first noise component of the gain stage (710), storing the first signal (725), generating a second signal comprising a desired output component and the first noise component (730), and subtracting the first signal from the second signal to produce a first output signal having the desired output component (750).

Dependencies are inferred from the claim text.